The present invention relates to an adjustable spring-driven pusher device for use on a forward feeding merchandise display shelf to dispense articles one by one from a front, or dispensing end, of the shelf, and more particularly, the present invention relates to a spring-driven pusher device that can be set to provide a predetermined amount of pushing force adjustable within a range of pushing forces.
Many stores, particularly retail stores, outlet stores and the like, store and display products on shelves from which purchasers can select and remove one or more of the products from the shelves. Such shelves are typically provided with a forward feeding pusher device so that a substantially horizontal stacked row of identical products located in front of the pusher device is biased toward the front end, or dispensing end, of the shelf to force the products remaining in the row to be pushed forward when one of the products from the front end of the shelf is removed. In such a forward feeding device, the pusher can extend upwardly from a track located below the products, downwardly from a track located above the products, or laterally from a track extending adjacent the sides of the products. Alternatively, the pusher device can extend from a substantially vertical track and be utilized to up-feed, or down feed, a vertically stacked column of products.
Examples of such merchandiser assemblies are disclosed in U.S. Pat. No.: 4,303,162 issued to Suttles; U.S. Pat. No. 5,634,564 issued to Spamer et al.; U.S. Pat. No. 5,012,936 issued to Crum U.S. Pat. No. 5,562,217 issued to Salveson et al.; U.S. Pat. No. 5,878,895 issued to Springs; and U.S. Pat. No. 5,131,563 issued to Yablans.
One problem presented by the use of such merchandiser assemblies is that the product being stored and displayed often range significantly in size, shape, surface texture, and weight. For example, some products are lightweight and sold in relatively small rectangular boxes or cartons (ie. breakfast cereals), whereas other products may be relatively heavy and be packaged in plastic containers or the like (ie. bottles of motor oil). Thus, depending on which product is to be stored and displayed on a particular shelf, a spring providing a desired amount of pushing force must be selected and installed in the spring-driven pusher device. For example, a spring sufficiently strong to forward feed relatively heavy items, or items which resist sliding, may be too strong for use in feeding relatively lightweight or readily slidable items, and conversely, a spring sufficient to forward feed relatively lightweight items may not be capable of pushing relatively heavy items.
Therefore, there exists a need for a universal spring-driven pusher device which can provide a selected pushing force within a wide range of forces so that the same spring-driven pusher device can be used in connection with products that range significantly in size, shape, surface texture and weight.
U.S. Pat. No. 4,303,162 issued to Suttles, cited above, discloses a forward feeding merchandising device for soft drink bottles. The Suttles patent discloses a pusher device driven by a positive gradient, ie. variable force, self-coiling metal spring. The Suttles patent states that a positive gradient spring is preferred since it exerts greater force when fully extended and less force as the spring becomes further retracted. In addition, the Suttles patent discloses the use of an adjustable angled pusher plate which can be utilized to adjust the pushing force provided by the spring-drive pusher device. To this end, the Suttles patent states that the force is maximized hen the plate extends perpendicular from the track and is reduced when the plate is bent forward to reduce the angle formed between the plate and the track. See column 7, line 44, to column 8, line 2, of the Suttles patent.
U.S. Pat. No. 5,634,564 issued to Spamer et al., cited above, discloses another spring -driven pusher device for dispensing articles. The Spamer patent discloses the use of a self-coiling metal spring having a two-stage structure. The spring has a coiled end portion with innermost windings acting as a constant force spring and outermost windings acting as a variable force spring. See FIG. 12 and column 7, lines 6-65, of the Spamer patent. According to Spamer, the purpose of the constant force spring inner windings is to prevent excessive force from being exerted on a fully loaded row of articles.
Although the above referenced merchandiser assemblies having spring-driven pusher devices may be satisfactory for their intended purposes, there is a need for a novel universal spring-driven pusher device which permits ready adjustment of the pushing force provided by the pusher device so that, when a shelf is utilized to store and display a different product type, the same pusher device and spring can be utilized regardless of the shape, weight, surface texture, or size of the newly stored and displayed product. Further, the pushing force should be capable of ready and precise adjustment within fine increments so that the universal spring-driven pusher device can be set to provide a proper amount of pushing force specifically required for the selected product. In addition, the spring-loaded pusher device should be inexpensive to manufacture and easy to adjust.
With the foregoing in mind, a primary object of the present invention is to provide a novel universal spring-driven pusher device which can be utilized to forward-fee, up-feed, top-feed, or side-feed merchandise in a dispenser for products within a great range of weights, sizes, shapes, and surface textures and which does not require replacement when one type of merchandise in the dispenser is replaced with another type of merchandise significantly different in weight, size, shape and/or surface texture.
Another object of the present invention is to provide a novel spring-driven pusher device which enables accurate incremental adjustment of pushing force within a wide range of forces.
A further object of the present invention is to provide a method of adjusting the pushing force provided by a spring-driven pusher device, the method should require only a minimum of effort and skill and permit ready adjustment in a minimum of time.
A still further object of the present invention is to provide an adjustable spring-driven pusher device which can be readily manufactured in a cost efficient manner.
More specifically, the present invention provides a spring-driven pusher device for an article dispenser that includes an elongate track having a dispensing end and an opposite end and an elongate surface for positioning a row of articles for movement therealong between the dispensing end and the opposite end of the track. The track can be disposed parallel or perpendicular to the horizontal or at any angle relative to the horizontal and can be positioned below, above, or adjacent the sides of the articles being dispensed. A pusher extends outwardly from the track and is connected to the track for movement lengthwise along the track between the dispensing and opposite ends for urging the row of articles toward the dispensing end of the track.
Preferably, a flat metal self-coiling spring, such as a steel variable force spring or a steel power spring or a flat elongate strip of metal which is placed in a coiled condition, exerts a force on the pusher to urge the pusher toward the dispensing end of the track. To this end, the spring, or trip, has a coiled end portion that is carried on the pusher and an opposite uncoiled end portion which is connected to the track. Alternatively, the spring, or strip, has a coiled end portion that is connected to the track and an uncoiled end portion which is carried on the pusher. The coiled end portion includes multiple windings under tension about an axis and a terminal end located adjacent the axis. Preferably, a slotted arbor extends along the axis of the coiled end portion and is connected to the terminal end of the coiled end portion. Alternatively, the terminal end portion can be connected to the arbor with a screw or like fastening device.
The arbor is rotatably mounted to one of the pusher or the track so that the tension of the windings of the coiled end portion is adjustable by rotation of the arbor. Thus, the pushing force provided by the spring, or strip, of the pushing device is readily adjustable in a store by store personnel by increasing or reducing the tension of the winding the coiled end portion of the spring, or strip.
According to another aspect of the present invention, a method is provided for loading a forward, side, top, or up feeding merchandising apparatus. The method includes the step of positioning a row, or column, of articles in front of, or on top of, a pusher device. The pusher extends transversely to a path of movement of the articles for movement lengthwise along a track between the dispensing end and opposite end of the track and urges the articles toward the dispensing end. In addition, the method includes the step of setting the pusher to provide a desired amount of pushing force. To this end, the pusher is connected to a self-coiling variable force spring, a self-coiling power spring or a flat strip of metal positioned in a coiled condition.
The self-coiling spring, or strip, has a coiled end portion with multiple windings under tension, and the step of setting the pusher includes adjusting the tension of the windings of the coiled end portion of the spring, or strip. Preferably, the pusher includes a rotatable arbor extending along an axis of the coiled end portion, and a terminal end of the coiled end portion is mounted on the arbor for rotation with the arbor. The step of setting the pusher includes rotating the arbor to adjust the tension of the windings of the coiled end portion. In addition, preferably the step of setting the pusher includes locking the arbor in a condition which prevents rotation of the arbor about the axis of the coiled end portion after a desired tension of the windings is set.